Piano Roll is a sequencer for iOS, and the first in our Atom series of modular sequencer plugins. Record, replay, loop and manipulate MIDI notes anywhere.

The MIDI audio unit can be loaded in compatible hosts (AUM, ApeMatrix, Audiobus, BeatMaker 3, Cubasis 2, etc.). Make sure your host is capable of loading, transmitting to, and receiving MIDI from audio unit MIDI plugins.

It’s intended to augment existing MIDI processing capabilities, or in scenarios where a host doesn’t provide sequencing functionality out of the box.


1) Loop record
Grow your ideas over any number of bars. Overdub drum loops, layer complex melodies, or even record an entire track. Arm recording in multiple instances, in the background, receiving from hardware or even other audio units. Piano Roll is always sample accurately synced with the host.

2) Step input
Quickly create sequences. Insert notes respecting grid length, and resize them to any duration. Layer chords in one operation. Just send the notes, Piano Roll takes care of the rest.

3) Extensive editing tools
All the standard editing tools you are used to are implemented, pen for entering notes at any length, brush for painting continual notes at grid size and scissors for slicing.

Advanced tools allow you to be productive. Grow notes backwards or forwards. Group notes with additive selection. Select rows or chords in one operation. Time and pitch flip. Velocity editing is precise and unobtrusive. With Piano Roll, anything you need is a tap, hold, or swipe away.

3) Non destructive quantize
Quantised or not? You decide when, and how much! Enable full quantisation beforehand with grid snapping. Turn it back off, or adjust the strength afterwards on an already recorded sequence. Choose the quantisation percentage for note starts, note ends and even note durations. In Piano Roll, you have full control over timing precision.

4) Dynamic stretching
Stretch a clip from 4 bars to 8. Fix the note lengths or extend them in harmony. In Piano Roll, your sequences are elastic.

5) Advanced time signatures
Does 4/4 sound boring to you? Create complex polyrhythms by choosing any timing. From 3/8 to 11/8. From 2/1 to 17/16. Piano Roll lets you invent your own rhythm.

6) Advanced tempo settings
Negative BPM? No problem. Pick a tempo for every clip and play backwards or forwards. Multiply host tempo or choose something arbitrary, all with extreme accuracy. Piano Roll gives you control over tempo like never before.

7) Scales
Never go outside a scale, or go chromatic and add spice to the melody. With scale overlays, your music isn’t forced to sound in a predetermined way, and you aren’t forced to be a music theory genius to sound the way you want. Piano Roll gives you the ability to decide in which key to be and when.

8) Visibility layers
Aid composition by overlaying other clips from other plugin instances over the one you’re editing. Make sure your chords are in harmony with the melody, visually. Piano Roll roll helps you focus where you need, when you need it.

10) State saving
Your sequences are saved alongside the project you already work with. And they’re loaded back automatically when opening up a project. Clips can be saved as host presets. Piano Roll is in perfect harmony with the host you already use.

What’s New

Version 1.0.1

- Fixed rendering issues on iOS 11
- Layout improvements for small screen sizes
- Note entry improvements for right-to-left gestures
- History stack improvements for flip operations
- Various other small quality of life improvements

Ratings and Reviews

4.5 out of 5
36 Ratings

36 Ratings

wareismike ,

Landmark Addition to iOS Music Making!

At last! A modular way to easily record, edit, and loop midi in iOS. If you’re at all into creating on the fly in hosts like AudioBus, AUM, and ApeMatrix, which have no built-in midi recording and editing, this changes everything!

Not only that, but Atom Piano Roll is about as perfect an implementation as you will ever find on iOS. It’s not as feature complete as it will be in the coming months, but it has the essentials, and it has them flawlessly executed.

Likewise, if you normally use one or more timeline based DAWs, but aren’t happy with their midi editing, you owe it to yourself to check this out. I know that except for two apps, I will be using Atom as a replacement for the piano roll editors that I just don’t get along with.

I could not be happier with this purchase!!

Nivekevil ,

Wonderful app. Two requests.

Yeah, so, this easily wins the iOS AU sequencing game. Layering works flawlessly, but honestly I’m most blown away by the tempo scaling. Freaking fantastic for live recording into an Elektron sequencer with micro-timing. Buy this.

Now, two requests:

1. Native midi channel filtering for output. This is easy enough to work around in Audiobus, but it’s something of a nightmare in AUM when sending out to external hardware. Please let me set each clip to a specific channel.

2. Patterns per clip. Simple enough. This is well implemented in StepPolyArp, and similar functionality in Atom would be fantastic.

Again, quibbles aside this is a killer app and if you’re looking for sequencing it should be for first stop.

capedape ,

iOS music making is getting “pro” tools.

Love being able to have multiple AU instances of this connected to one synth app to do counterpoint etc.

This app connected in hosts like AUM and Beat Maker 3 is REALLY opening up iOS music making to so many possibilities. Been releasing music with DAW workstations forever, but find myself going to iOS first because it’s becoming more immediate and fun. Looking forward to that Ableton like clip launcher by the developer that’s apparently in the works.

Also, to the developer, would be cool if we could hear the note on entry like in Korg Gadget. Tap to enter and double tap to delete too.

That said, cheers and thanks for this good stuff!


Victor Porof
14.3 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2019 Victor Porof


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

More By This Developer

You May Also Like